gantt-chart-generator

Generate horizontal Gantt charts from schedule data via the bundled scripts/gantt.py toolkit. The gantt() function accepts a DataFrame or file path plus column names, and saves a PNG (returning the path). It handles theming, date parsing, bar colour-coding, completion overlays, today-line, legend, and saving.

Instructions

1. Provide the data source: a pandas DataFrame, or a path to a .csv / .tsv / .json file.

   • One row = one task / phase.
   • Required columns: a phase/task name column, a start date column, and either an end date column OR a duration-in-days column.

2. Import and call gantt():

import sys
sys.path.insert(0, "scripts")   # adjust path to where gantt.py is deployed
from gantt import gantt

Basic — start + end columns

gantt("schedule.csv", phase="Phase", start="Start", end="End", title="Project Schedule", out="gantt.png")

Group colour-coding + today line

gantt(df, phase="phase", start="planned_start", end="planned_end", group="project", today=True, out="schedule.png")

Duration instead of end date

gantt(df, phase="task", start="start_date", duration="days", out="schedule.png")

Completion % hatch overlay

gantt(df, phase="Phase", start="Start", end="End", completion="PctDone", out="gantt.png")

3. See `references/cheatsheet.md` for full parameter reference and CLI examples.

## Bundled files
- `scripts/gantt.py`      — the full toolkit (load_data, apply_theme, save_fig, gantt, CLI)
- `references/cheatsheet.md` — parameter quick-reference and copy-paste examples
- `assets/sample_schedule.csv` — demo dataset that exercises every feature

## Defaults & behaviour
- Colorblind-friendly palette (matches chart-builder skill for visual consistency).
- Date axis auto-scales: weekly ticks ≤90 days, monthly ≤365 days, bi-monthly beyond.
- Bars ordered top-to-bottom matching input row order.
- Rows with missing phase or start values are silently dropped before drawing.
- Output PNG at 150 DPI by default.
- Provide `end` OR `duration` — not both; `end` takes priority if both are present.